A dishwasher is a home appliance that uses a washing pump to pump out washing water. The washing water pumped out from the washing pump is sprayed from spray nozzles to wash dishes loaded in upper and lower racks. The dishes washed are dried. The dishwasher includes a tub defining an outer appearance of the dishwasher, dish racks disposed inside the tub for placing dishes thereupon in a predetermined arrangement, spray nozzles for spraying washing water onto the surfaces of the dishes, and a sump installed at the bottom of the tub for storing washing water.
A heater is installed on a surface inside the sump for heating washing water flowing into the sump, and a turbidity sensor is installed at a location where washing water flows inside the sump for sensing the impurity level of the washing water during a wash cycle. When the pollution level of washing water exceeds a preset level, the washing water is drained, and fresh washing water is drawn in.
Also, the dishwasher pressurizes the washing water spray from the spray nozzles to remove food reside from dishes, and the food residue removed from the surfaces of the dishes falls to collect on the floor of the tub. A filter for filtering the foreign objects is installed at the top of the sump, to ensure that a large resistance to the flow of washing water is not imposed by large foreign objects entering and sticking inside the sump. To prevent the above, a disposer for pureeing large foreign objects is installed inside the sump. Thus, the blockage of washing water passages by foreign objects during the flowing of washing water stored in the sump to the spray nozzles can be prevented.
However, sumps of dishwashers according to the related art have limited space in which to store washing water, and can only store small amounts of washing water.
In addition, in some dishwashers, since the heater for heating washing water entering the sump is installed outside the sump, the overall size of the dishwasher increases.
Furthermore, because dishwashers according to the related art have marginally effective filters, food residue and other foreign objects that occur during a wash cycle can enter the spray nozzles and clog the spray holes thereof.